The effects of weak power on the morphology of α-Al phase in slurry and radial distribution of microstructure of slurry which was prepared by low super-heating pouring and weak electromagnetic stirring have been observed.The results indicate that the AlSi7Mg alloy slurry with 127 μm in diameters and uniformly distributed microstructure in which fine spherical primary α-Al phase is generated can be prepared successfully with pouring at 630 ℃ and stirring power of 0.36 kW in the condition of low super-heating pouring and weak electromagnetic stirring.Meanwhile

the morphology of primary α-Al phase can be further spheroidized with the increase of stirring power

however

it has been little improved with the stirring power increase to a certain value.The microstructure of semi-solid AlSi7Mg alloy slurry is converted from dendrite into rosette-like structure into spherical structure from edge to center of slurry in radial direction.